Square.



G W. BOWERS.

SQUARE.

APPLICATION FILED MAY 28, 1912.

Patented Sept. 16, 1913.

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Geo?" ewjowe zrs, a

G. W. BOWERS.

SQUARE.

APPLICATION FILED MAY 28, 1912.

Patented Sept. 16, 1913.

2 SHEETS-SHEET 2.

22 360 [Ml/Z1 6 :10. T /55 o ,Lm'uev c or I A 70 g gyewfiowers,

GEORGE W. BOWERS. F SOMERVl'iiLE, MASSACHUSETTS SQUARE.

Specification of Letters Patent.

Application filed May 28, 1912. Serial No. 700,203.

Patented Sept. 16, 1913.

To all whom 1' I may concern Be it known that I, Gnonon WV. BOWERS, a

citizen of the United States, and a resident of Somerville, in the county of Middlesex sand State of lVlassac-husetts, have invented certain new and useful Improvements in Squares, of which the following is'a specification. This invention relates to measuring inm strumcnts of the type employed for determining the accuracy of angles, such instruments being sometimes of a form commonly called try squares.

With the ordinary square used for testiug the angles formed by two surfaces supposed to be at right angles with each other, the determining angular edges of the square, even if at accurate right angles with each other, cannot be employed to determine the accuracy of the two surfaces of the article to be measured excepting within such limits as may be determined by the power of the human eye to note the transmission of the light between the edges of the square and the surfaces to be measured.

The object of the present invention is to provide an improved instrument of this character which will enable the accuracy of the angles of the surfaces to be measured to '30 an unquestionable determination without relying upon the transmission of light between the edges of the instrument and the surfaces of the article.

To these ends the invention consists in the 315 square having two bearing oints to contact with one of the angular sur aces of the art-icle to be measured or tested, one ofsaid bearing points being movably connected with the body of the square, means being employed to determine the extent of move' ment of said movable bearing point.

The invention further consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings z- -Figure construction of the slide and indicator. Fig.

7 is a detail view of the slide mechanism shown in Fig. 6, on a larger scale and with the front plate removed. Fig. 8 represents 0 a sectionon line 88 of Fig. 7. Fig. 9 is a detail view of the spring shown in Fig. 7. Fig. 10 is an elevation from the. right of Fig. 7. Fig. 11 is a detail elevation of the pivot pin for the lever or rocking arm shown 5 in Fig. 7. Fig. 12 is a detail view of the frictional gib and its screw.

The same reference characters indicate the same parts in all the figures.

Referring first to Figs. 1, 2 and 3, the body of the square comprises a beam 20 and blade 21, it being understood that either the under surface or the top surface of the beam 20 is to be employed to contact with one surface of the article to be tested.

In the embodiment of the invention shown in Fig. 1, there is a toe 22 projecting laterally from the angle of the square, and rigidly connected thereto as by a rivetpassing either through an edge portion of the blade 21 or through a portion of the beam 20. This toe 22 forms one of the bearing points to contact with a portion'of one of the surfaces of the article to be tested, such surface being indicated by the dotted line a when the base of the beam 20 is hearing against a surface 6 of the article to be tested. Another toe 28 is secured at the inner angle of the square, the purpose of which will be hereinafter described. Mounted on the blade 21 is a slide carrying an indicator, the position of which is affected by a movable bearing point or toe 24, the mechanism as will be presently described, being such that if the surface a is not accurately at a right angle with the surface 6, the indicator will. show at either the minus or plus side of. the zero or test point, how much out of true ang'ularity the surface a is in relation to the surface I The body25 of the slide is milled out or otherwise formed, as indicated in Fig. 3, to receive the blade 21. In order that said slide may be held at any desired point lengthwise of the blade 21, I provide a gib 26 which is adapted to be pressed by means of a screw 27 havin a milled head,- against one edge of the blade 21. A strip 28 is secured as by suitable rivets 29 between the front and. rear surfaces of the body 25 formed by milling. outthe passage way for the blade 21, there being a slight space .pro-

vided between the strip2 8 and gib 26 to permit the necessary movement of the gib in order to release or clamp the slide. To .hold the gib in position, it is provided with a notchindicated by dotted lines in Fig. 2, a pin'3O extending into said notch. Preferably the upper and lower ends of the inner edge of the il) 26 are slightly round or curved, as indicated by dotted lines in Fig. 2, to facilitate the placing of the slide on to the end of the blade 21 when assembling in either one of the vaiious pgsitions for said slide hereinafter described.

The body of the slide is cut away as at 31 to provide a space for an arm 32 pivoted at 33, the lower end of said arm which projects outwardly from the slide constituting a movable toe 24. The other end of the arm 32 is formed or provided with a toothed sector 34 which meshes with a pinion on an arbor' 35 suitably mounted in the slide and in the cover plate-'36, the outer end of said arbor having a pointer 37 adapted to 006p crate with a dial 38 secured to the outer face of the cover plate 36. A hair spring 39 is employed to insure accuracy of movement of the pointer under the control of the arm 32 and its sector 34. The dial is held in place by a ring 40 secured'to the cover plate 36 as by screws 41. Said ring 40 is shown as carrying a bezel and crystal to protect the thousandth of an inch or less.

pointer 37-but permitting it and the graduations on the dial to be seen In practice, the dial may be graduated to indicate one- The cover plate 36' is secured to the body of the slide as by screws 42, and also by the screws 41.

By means of the screw 27 the slide may be set at any point'alon the length of the blade 21 according to t e size of the surface a, and the distance at whlch it is de-' sired that the movable toe 0r bearing int 24 shall be from the toe 22. In Fig. 1 the toe 24 is shown as crossing thedotted line 0;, because in said figure the said toe 24 is sup- .posed to occupy its normal. position under the influence of spring 39, said normal osition being also shown in Fig.2. If, 0

ever, the square is-tobe used to test theaccuracy of the angular relationshi of the surfaces 11 and b, the placing of sai square in position relatively to'said surfaces in the j same mannerin which the ordinary square 1s-used, will result in the toe-24 being moved in such a direction that thetoothed sector '34 will rotate the pointer towardthe zero point indicated at w in Fig. 1. The strucacute, and the amount of the obtuseness or acuteness will be accurately indicated by the pointer 37. It will be readil understood that it is much easier to per orm this testing operation, by reading the indications of the. pointer, than by relying upon the transmission of light rays between the edge portions of the square and the surfaces being tested. In Fig. 1, dotted lines indicate two other positions that may be given to the slide relatively to the blade 21, other than the mere adjustmentof the slidelengthwise of the blade. The lower dotted lines of Fig. 1 indicate how the slide ma be mounted as by sliding it 011 from the b ade 21, turning it one-half way around, and returning it with the toe 24 projectin inwardly over the toe 23. This is to enabl e to be used to determine the accuracy of the angularity of two external faces of an article bearin with one face against the u'gper surface 0 beam 20 andwith another ace bearing a. ainst the tip of toe 23. The operation wi then be the sameas already described, excepting that the toe 24 cooperates with the toe 23.1nstead ofwith the toe 22' in determining the accuracy of the angle of the side face of the an le to be tested relatively to the under sur ace of such article.

If the height of the side face of the article be greater thancould be tested if the slide were moved upwardl as far as possible along the blade 21 an while said slide is in position shown by full lines in Fig. 1, then the slide can be removed and turned onethe instrument half way over vertically so as to enable the toe 24 to occupy the position shown by dotted lines at the extreme top of-Fig. 1.

With the construction. shown in Figs. 1,

2 and 3 it may be necessary sometimes to adjust the dial relatively in order to locate the zero point properly. Instead of doing v this, however, I may make the movable bearing point adjustable. This may be effected, as indicatedin'Fig. 4 by construct ing the bearing point as a" screw, the head 24 of which is to bear against the surface to bemeasured, said screw being tapped- H into the lever or arm 32 andsecured in'adjusted position by a jam nut or lock nut 43.

To provide means for accurately .deter- 4 mining the normal position of the arm 32 andto limit the distance to which said'arm canbemoved away from normal po'sltion, said am is 'pi'jgvided. with pro ect1ons 44 adapted'to contact,with the walls of the recess or cut away portion 31.

The toes 2 fand 33 neednot beseparate Iv pieces riveted in position, but may be inf 1'- different from that shown in Figs. 1, 2 and 3. In this modified form the slide comprises a-body 250 milled out to provide ways Lowrance I a for the edges of the blade 21, asbest shown vin Fig. 8. A gib.26(l (Figs. 7, 8 and 12) is provided with' a screw 270 extending across a recess formed in a projecting portion of the body of the slide. A milled nut 271 is mounted on the screw 270 so that owing to the engagement of the'nut with the walls of the recess in which it is mountedsaid nut may be utilized for adjusting the gl-b 260 to cause it to frictionallybind against the edge of the blade 21. The pro-" jection shown in Fig. 7 is provided with I indications such as the letters L T to indicate which .way to turnthe nut 271 to 15 loosen or tighten the of the body of the slide is milled out to receive an. arm 320 pivotally supported on a taper pin- 330 and having a toe 240. The pivot pin 330 is tapered as shown'in Fig. 11

so that it may be driven tightly into either the hole provided .therefonin the arm 320 or in the hole or holes formed in the body of the slide, The upper end of the arm 320 is provided with a pin 340 which projects through a laterally elongated hole in the sidev ofthe body of the slide, said pin 340 engaging the short arm 50 of a lever pivoted at 51 and having a long arm 52, the outer end of which extends under a pin 53,

carried by a short, arm of an elbow lever pivoted at 54 to the body of the slide and having a longer arm 55 which constitutes a pointer. The extreme end of the pointer arm 55 may 'be provided with a scored or otherwise formed mark to coeperate with the zero p01n t 11 carried by a scale strip '56. In order that said scale strip may be .adjusted'in its position, its ends may be, as shown in Fig. 7 provided with slots'throu h which screws 5 ?pass into the body of t e slide. A spring 58 (Figs. 7 and 9) is provided withan eye 59 mounted on a pivot pin or screw 60, and the short end of the said spring bears upon the pin 340 while the longer end bears upon the pin, 53 and causes the latter to follow all movements of i the lever arm 52. A cover plate 360 shown -by' full lines in Figs. 6 and 10 and indicated by dotted lines in'Fig. 8, is secured to the body of the slide by any suitable means such as by screws. It is provided with a sight opening 61 through which the end of the pointer arm 55 may be seen, and

its position relatively to the'scale strip 56 55 determined. As indicated in Fig. Gby the several different dotted lined positions of the slide and indicator relatively to the-- blade 21, the use of this device is practically the same as has been described in connec 60 tion with. Fig. 1.- The coiiperation of the several toes. with the portions of the .work

to be tested will be the same as described in connection with Fig. 1, but instead of a circular dial and a pointer actuated by a 5 toothed sector, the pointer arm- 55 is actugib. The other edgeated'to a position that may be plus or minus relative .to the zero point a: through the arm 320, its pin340, the arms 50, 52' of the intermediate lever, and the pin 53 and spring 58. Practically the use and operation of 7.

this structure of the square will be thesame as that illustrated in Figs. 1 and 2. f

Instead of providing toes 22, 23 as shown in Figs. 1 5,, and 6 I may. employ separate, detahhed test blocks such as indimanner described in connection with Fig. l. 5

WhileI have illustrated the invention as an attachment for, or as a part of an instrmnent mmonly kn w as a square it is to be understood that the members. 20,

21, or their equivalents, may be at any other than a right angle, so as to constitute an angle instrument.

'VVhether the instrument is. termed a square or an angle it comprises a beam and a blade as explained. \The toe 22 or the toe 23, whether a fixed or separate projection or test block, constitutes a stop which determines or limits the testing position of the bottom of the\ article that is i being measured or tested longitudinally of the beam. Such stop device is essential for the reason that, if absent, an article the two sides of which were at an angle more obtuse than the degree of angle provided for by the beam and blade could not be accurately tested.

I Claim: v 1. A square for determining the accuracy of angles between plane surfaces, comprising a beam and a blade the blade being at one end of the beam and the two at right angles to each' other, the beam having a plane surface to contact with one of the two surfaces the-angle between which is to be tested, a stop to contact with a portion of the other of said two surfaces, a -bear1ngpoint supported on the blade to contact with I another portion of the surface which receives the contact of said stop, and an indicator operatively connected with said bearing point.

2. An instrument for determining the accuracy of angles between plane surfaces, said instrument comprising two relatively rigid members at an angle to each other, two projections extending beyond the edge of one of said members, to contact with one of the two surfaces the angle between which is to be tested, oneof-said projections being movable toward and from said edge and the i other projection having its tip at a fixed distance from said edge, and an indicator operatively connected with said movable projection.

3. An instrument for determining the accuracy of angles between plane surfaces, said instrumentcomprising two relatively rigid members at an angle to each other, two projections extending beyond the edge of one of said members, to contact with one of the two surfaces the angle between which is to be tested, one of said projections being movable toward and from said edge and the other projection having its tip at a fixed distance fromsaid edge, and an indicator operatively connected with said movable projection, and means slidably 'mounted on the blade and carrying said movable projection and indicator.

4. An instrument for determining the ac curacy of angles between plane surfaces,

said instrument comprising two relatively rigid members at an angle to each other, two projections extending beyond the edge of one of said members, to contact with one of the two surfaces the angle between which is to be tested, a slide mounted on one of the members of the instrument and carrying one of said projections, the projection carried by said slide being movable toward and from said edge and the other projection having its tip at a fixed distance from said edge, and an indicator carried by said slide and operatively connected with the movable projection.

In testimony whereof I have aflixed my signature, in presence of two witnesses.

GEORGE W. BOWERS.

Witnesses:

A. W. HARRISON, P. W. Pnzzm'rl; 

